What is it?
While we’ve found reason in the past to censure BMW for its blind spot when it came to four-wheel drive in right-hand-drive saloons, the discrepancy wasn’t often mentioned with regard to its big-ticket flagship. That’s because the 7 Series, like most cars its size, has always been squarely focused on the formal business of cosseting and carriaging the wealthy - not gamely scrabbling for traction in extremis.
Nevertheless, in parts of the world that resemble a chest freezer for half of the year, such a 7-Series has been available now for a generation. Consequently, with its latest platform properly prepped for it, BMW’s rear-bias xDrive arrangement finally makes it to the UK version. The drivetrain is actually available on the entry-level 730d - although not the long wheelbase variant. If you want the stretch with four-wheel-drive, you’ll need to upgrade to the 740Ld - the model we test here.
What's it like?
No matter which version you choose, you’re unlikely to register much difference in everyday driving. That’s because a) the adaptive xDrive system defaults the shove to the back axle anyway, and b) the 7 Series - even in standard configuration - would prefer its driver (and passengers) to register only perpetual, indeterminate waft; not the grimy specifics of how it actually operates.
In this respect, the 740Ld is a worthily serene old Panzer. The engine is the same oil-burning 3.0-litre turbocharged straight-six we road tested last year in 730d format, but with the power increased from 261bhp to 316bhp, including an additional 44lb ft of torque.
The upgrade is a likable one, throatily maturing the 7-Series from capable two-tonne cruiser to utterly self-assured dreadnought. There’s no indecorum to the higher output (perish the thought) just a pleasant sense that the motor and eight-speed auto are labouring less under the mass of the car.
Adding the modest extra weight of the xDrive system has done nothing to harm the model’s self-leveling ride quality either, which on 18in wheels and winter tyres, seemed better behaved at low speeds than we remember.
Any perceptible shuffling of the power between axles is limited on dry surfaces to the kind of vigorous pull aways no chauffeur would chance his cap on. Do so though, and, predictably, the car surges forward more cleanly than its rear-drive stablemate would. Similarly, if you insist on it, aggressive work up to an apex can be attempted with more confidence; the traction and positivity of the front axle having been duly enhanced.
The real boon though - one only realised in a two-minute unmade, snowy incline during a seven-hour drive - is the 740Ld’s impassive response to finding something less consistent than tarmac under its rubber.
With minimum fuss, and with the comfort-orientated adaptive air suspension merrily replicating the gloopy body movement of a much taller SUV, our limo found the necessary purchase to make a potentially embarrassing slippery climb a complete non-event. Which, of course, is the whole point.